Duplex propeller.



No. 715,!91. Patented Dec. 2, I902.

H B. ALLISON.

DUPLEX PBDPELLER.

m ucmn filed June 10, 1902.

(No Model.)

UNITED STATES HUGH B. ALLISON, OF DES MOINES, IOWA.

PATENT OFFICE.

DUPLEXPROPELLER.

SPECIFICATION forming part of Letters Patent No. 715,191, dated December 2, 1902.

Application filed June 10, 1902. Serial No. 110,990. (No model.)

To (tZZ whom it may concern.-

Be it known that 1, HUGE B. ALLISON, a citizen of the United States, residing at Des Moines, in the county of Polk and State of Iowa, have invented a new and useful Duplex Propeller for Marine'Vessels, of which the following is a specification.

My object is to increase the speed of boats and other marine vessels and diminish the quantity of fuel required for operating propellers and to reduce the friction of propelling-blades in dipping in and out of the water and to save time and expense in navigating rivers, lakes, and oceans for transporting persons and freight by means of vessels adapted for such purposes.

My invention consists in the construction, arrangement, and combination of two propeller-wheels with a frame fixed to the stern of a vessel and operating mechanism of an engine on the vessel, as hereinafter set forth, pointed out by my claims, and illustrated by the accompanying drawings, in which- Figure 1 is a diagrammatical view of one of the paddles of my propeller-wheel. Fig. 2 is a plan view of one of the propeller-wheels. Fig. 3 is a top view ofthe stern of a vessel to which my duplex propeller is applied as re quired for practical use.

The numerals 10 designate the paddles of the propeller-wheels, that may vary in size as desired. They are fixed to hubs 12 in any suitable way as required to extend radially at equal distances apart. Their outer end portions are inclined laterally relativeto their inner fixed end portions, and their extremities are tapering and terminate in points adapted for readily entering the water as required to graduate resistance, so that there will be less opposition and strain at their narrowed and pointed end portions than at their central and wider portions. By virtue of their lateral inclinations relative to the axis of the wheel and the line of advance of a vessel the resistance of the water is exerted in a direction at right angles to the axis of the wheel as required to move the vessel backward or forward, and by inclining the two wheels in opposite direction relative to each other and thevesseh'as shown in Fig. 3, they will coact in producing a balanced propelling force that will be in alinement with the longitudinal eenterof the vessel and the line of its advance.

A frame composed of mating and portions 13 and 14 and a cross-bar 15, as shown in Fig. 3, or in any suitable way, is fixed to the stern of a vessel about the water-line to extend horizontally, and a rotatable shaft 16, provided with cranks at its ends, is designed to be connected with an engine on the vessel by means of pitman-rods 17 and 18 or in any suitsmaller diameter than the wheels 19 and 20 on the shaft 16, are fixed to the shafts 21 and 22 for transmitting power to the propeller-wheels to rotate them toward each other in vertical planes that are inclined relative to the line of advance as required to enact in dipping their paddles and pressing and applying the resisting force of the water to propel the vessel.

It is obvious the power of my duplex propeller may be varied by the length and width of the paddles and the speed of the propellerwheels regulated by the difference in sizeof the beveled wheels on their axles and the beveled driving-wheels that engage them.

Having thus described the purpose, construction, application, and operation of my invention, its practical utility will be understood by persons familiar with the art to which it pertains, and

What I claim as new, and desire to scour by Letters Patent, is-

1. In a propeller-wheel for vessels, a padwheel, and tapering at its inclined free end in the manner set forth for the purposes stated.

3. A propeller-Wheel for vessels comprising a hub and a plurality of paddles each consisting of an inner fiat portion projecting radially and at right angles to the axis of the hub and an outer free end fiat portion inclined to a longitudinal plane radial to the axis of the hub, in the manner set forth, for the purposes stated.

4. A duplex propeller for vessels comprising a frame adapted to support two propellerwheels in vertical planes that are inclined relative to the longitudinal and vertical center of the vessel, two propeller-Wheels of uninal plane radial to the axis ofthe hub and means for transmitting power and motion from an engine on a vessel to which the frame is fixed to rotate the propeller-wheels in reverse ways in the manner set forth for the purposes stated.

HUGH B. ALLISON. Witnesses:

R. H. ORWIG, THOMAS G. ORWIG. 

